[SCSI] fix kconfig dependency warnings related to SCSI_SAS_ATTRS

Fix kconfig dependency warnings in scsi/Kconfig:

warning: (SCSI_SAS_LIBSAS && SCSI || SCSI_MPT2SAS && SCSI_LOWLEVEL && PCI && SCSI || FUSION_SAS && FUSION && PCI && SCSI) selects SCSI_SAS_ATTRS which has unmet direct dependencies (SCSI && BLK_DEV_BSG)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/Kconfig

@@ -316,7 +316,8 @@ config SCSI_ISCSI_ATTRS
 
 config SCSI_SAS_ATTRS
 	tristate "SAS Transport Attributes"
-	depends on SCSI && BLK_DEV_BSG
+	depends on SCSI
+	select BLK_DEV_BSG
 	help
 	  If you wish to export transport-specific information about
 	  each attached SAS device to sysfs, say Y.